Methods and apparatus for facilitating the descent of well tools through deviated well bores



yum-Irv VU"U vvnnw 172i Inventor Walter E. Cubberly. Jr. [56] References Cited HousmmTex. UNITEDSTATESPATENTS 1 P 829,959 2,170,284 8/1939 Eastman l66/206X 1 Fried June3J969 2.l85,303 1/1940 Kinley l66/54.6 [45] Patented Dec. 29. 1970 7 T M I C 2,-l0,8l5 8/1940 Llnney 166/206 1 1 Asslgnee 3,371,741 3/1968 Haxbyw l66/206X New 3,401,749 9/1968 Daniel.... l66/77X 3,415,317 12/1968 Drivet 166/77X [54] METHODS AND APPARATUS FOR FACILITATING THE DESCENT OF WELL TOOLS THROUGH Primary Examiner-David H. Brown Attorneys-Ernest R. Archambeau, Jr., William J. Beard,

Stewart F. Moore, David L. Moseley, Edward M. Roney and William R. Sherman ABSTRACT: To practice the invention disclosed herein, a messenger sub including a pulley trailing a doubled hauling line is dispatched through a pipe string having its lower end positioned at a selected location in a deviated well bore. Once the messenger sub is operatively anchored in the well bore, the pipe string is removed to leave the hauling line extending along the well bore between the messenger sub and the surface. Thereafter, cable-suspended well tools can be coupled to the hauling line and readily moved thereby to selected positions within the well bore above the anchored messenger sub.

PATENTEU 051329 I970 SHEET 1 BF 2 Walter E. Cubber/y, J/T

A TTORNE Y PATENTEU 05229 I978 SHEET 2 OF 2 Walter E. Cubber/y, Jr lNVENTOR w wj A TTORNE Y METHODS AND APPARATUS FOR FACILITATING THE DESCENT OF WELL TOOLS THROUGH DEVIATED WELL BORES In some oil fields, it is not at all uncommon to find well bores having highly slanted intervals therein that may approach angles deviating from the vertical as much as 60 to 80. Similarly, well bores may often have obstructions therein, such as offsets or the like. It is, of course, all but impossible to simply lower a cable-suspended well tool to the bottom of such well bores. It will be appreciated, therefore, that unless suitable means and techniques are devised for moving cablesuspended well tools through such partially obstructed or deviated well bores, they simply cannot be logged or perforated in the usual manner.

Accordingly, it is an object of the present invention to provide new and improved methods for facilitating the descent of cable-suspended well tools through well bores having a highly deviated interval or other obstacles therein to the free travel of such tools.

It is another object of the present invention to provide new and improved apparatus for moving cable-suspended well tools into well bores presenting an obstacle, such as a highly deviated interval, to the free passage of such well tools.

These and other objects of the present invention are accomplished by new an improved apparatus including a messenger sub adapted to be moved through a hauling string in a well bore for carrying a doubled hauling line through the pipe string and selectively operable anchoring means adapted to anchor the messenger sub at a desired position in a well bore. In practicing the present invention, a pipe string is positioned in an obstructed well bore with its lower end at a selected depth. A messenger sub arranged in accordance with the invention and trailing a hauling line doubled over a pulley on the sub is dispatched from the surface along the interior of the pipe string for passing the hauling line through the pipe. In some embodiments of the invention, anchoring means are releasably connected to the pipe string and adapted to be coupled to the messenger sub once the anchoring means are engaged with the well bore wall. In other embodiments of the invention, anchoring means are arranged on the messenger sub for securing the messenger sub in the well bore below the pipe string. In either case, once the messenger sub is anchored is a selected location, the pipe string is removed to leave the doubled hauling line extending through the well bore between the anchoring means and the surface so that typical cablesuspended well-logging devices or other well-completion tools can then be pulled by the hauling line to any desired position within the well bore above the anchoring means,

The novel features of the present invention are set forth with particularity in the appended claims. The invention, together with further objects and advantages thereof, may be best understood by way of the following description of exemplary apparatus and methods employing the principles of the invention as illustrated in the accompanying drawings, in which:

FIGS. 1-4 successively depict the practice of the methods of the invention with one embodiment of apparatus arranged in accordance with the principles of the invention;

FIG. 5 shows an alternative embodiment of the new and improved apparatus of the present invention; and

FIG. 6 illustrates a modifies embodiment of the apparatus shown in FIG. 5.

Turning now to FIG. 1, a selectively operable anchoring device 10 dependently coupled to thelower end of a typical pipe string 11 (such as a plurality of tandemly connected joints of drill pipe) is shown as the anchoring device is being moved by the drill pipe along a highly deviated interval of a borehole 12 in which one or more completion operations are to be performed. In this particular embodiment of the apparatus of the present invention, the anchoring device 10 includes a central upright body, such as an elongated tubular housing 13 having transverse bars or partitions 14 and 15 across its upper and lower ends, carrying laterally extendible wall-anchoring means 16. To releasably secure the anchoring device 10 to the drill pipe 11, the upper end of thehousing 13 is loosely fitted within a collar 17 that is threadedly connected, as at 18, to the lower end of the drill string and coupled to the housing by means such as a pair of frangible shear pins 19 and 20. An upright projection or so-called fishing neck" 21 having an enlarged upper head 22 is mounted on top of the transverse partition 14 and extends upwardly inside of the lower end of the drill pipe 11 in coaxial alignment therewith.

The wall-anchoring means 16 include a pair of upwardly diverging rigid arms 23 and 24 that are operatively coupled at their lower ends to the housing 13 by means (such as a single transverse pivot pin 25 carried by an erect boss 26 on the lower partition 15) for enabling the arms to be pivoted outwardly from their retracted positions (FIG. 1) to their extended positions (FIG. 2). Longitudinal slots 27 and 28 are arranged on opposite sides of the housing 13 to accommodate the passage of the arms 23 and 24 as they are pivoted outwardly and downwardly therethrough to bring their sharpened upper ends 29 and 30 into anchoring engagement with the adjacent walls of the borehole 12.

To selectively drive the arms 23 and 24 outwardly in response to a predetermined manipulation of the drill string 11, an actuating member 31 is releasably secured (as by the shear pins 19 and 20) within the upper portion of the housing 13 and adapted for vertical movement therein between an elevated position (FIG. 1) and another position therebelow (FIG. 2). The actuating member 31 is, in turn, coupled to the arms 23 and 24 by a force-multiplying or toggle mechanism such as a pair of rigid links 32 and 33 that are pivotally connected, as at 34 and 35, between intermediate positions on the rigid wall-anchoring arms and a common transverse pivot 36 on a centrally located boss 37 depending from the slidable actuating member. Outwardly projecting transverse bars 38 and 39 on the actuating member 31 and extending through the longitudinal slots 27 and 28 in the housing 13 are adapted to be positioned justbelow the lower face of the collar 17 so long as the shear pins 19 and 20 are intact. Biasing means, such as a stout compression spring 40, are also preferably arranged between the housing 13 and the slidable actuating member 31 for urging the toggle links 32 and 33 and anchoring arms 23 and 24 downwardly once the shear pins 20 and 21 are disrupted.

Accordingly, as best seen in FIG. 2, once the anchoring device 10 has reached a desired position within the borehole 12, the pipe string 11 is manipulated to release the actuating member 31 for moving the pivoted wall-anchoring arms 23 and 24 outwardly and downwardly to anchoringly engage their upwardly directed pointed ends 29 and 30 with the adjacent borehole walls. In the preferred manner of accomplishing this with the anchoring device 10, the drill pipe 11 is lowered through the borehole 12 until reaching either the bottom thereof or some suitable weight-supporting barrier (such as a cement plug or the like) that has previously been placed therein.

In any event, by simply slacking off at least some of the weight of the drill pipe 11 that is supported in the usual fashion at the surface, the connecting collar 17 will be driven downwardly in relation to the stationary tool housing 13 until the shear pins 19 and 20 are broken. Then, as the drill string 11 moves further downwardly, the slidable actuating member 31 will be forced further downwardly in relation to the housing 13 as the coupling collar 17 engages the outstanding projections 38 and 39 on the actuating member. Downward movement of the slidable actuating member 31 will, of course, be effective (by way of the toggle links 32 and 33) to extend the rigid arms 23 and 24 outwardly through the elongated slots 27 and 28 and drive their sharpened upper ends 29 and 30 into the adjacent borehole walls. Moreover, once the shear pins 19 and 20 are broken, the compression spring 40 will also impose a significant downwardly acting force through the actuating member 31 and the toggle links 32 and 33 to maintain the rigid arms 23 and 24 securely anchored to the wall of the borehole 12 once the drill string 11 is removed. It will, therefore, be appreciated that once the points 29 and 30 of the arms 23 and 24 are firmly embedded within the wall of the borehole 12, the anchoring device will withstand substantial upward forces acting thereon without being displaced upwardly any significant distance.

As illustrated in FIG. 2, while the drill pipe 11 is still adjacent to or resting on the anchoring device 10, a messenger sub 41 is dispatched from the surface and moved downwardly through the drill pipe into coupling engagement with the anchoring device. In the illustrated embodiment, this messenger sub 41 is comprised of a body 42 adapted for passage through the drillstring 11 and to which is dependently secured one or more pairs of resiliently biased, opposed collet fingers 43 adapted to pass over the upright fishing neck 21 and become lockingly engaged around the enlarged head 22 thereon. A pair of laterally spaced upright brackets (only one shown at 44) are suitably arranged on the messenger body 42 to receive a pulley or sheave 45 that is journaled, as at 46,

between the upright brackets for rotation about a transverse axis.

For reasons that will subsequently become more apparent, a stout, flexible hauling line 47 of at least twice the length of the drill pipe 11 is doubled around the sheave 45 with both ends thereof trailing therebehind. In this manner, as the messenger sub 41 is dispatched downwardly through the drill pipe, the doubled hauling line 47 will be payed out from a suitable reel (not shown) at the surface and pulled into the drill pipe 11 by the messenger sub. It will be appreciated that application of a positive pressure to the surface end of the drill pipe 11 (as by pumping drilling fluids downwardly into the drill string) will be effective for moving the messenger sub 41 downwardly therethrough and pulling the trailing line 47 from its reel at the surface and on into the open upper end of the drill string. Although the significant flow restriction provided by the body 42 of the messenger sub 41 will generally suffice to effectuate reliable movement of the sub through the drill pipe 11, if desired, one or more sealing members such 'as typical swab cups (not shown in FIG. 2) may be mounted on the messenger body to provide a sliding fluid seal along the inner walls of the drill pipe.

It will be recognized, therefore, that once the messenger sub 41 has been securely coupled to the upstanding fishing neck 21 on the extended anchoring device 10, the drill pipe 11 may be removed from the borehole 12 to leave the doubled hauling line 47 extending therethrough from the sheave 45 to the surface. In one manner of accomplishing this, as one or more joints or so-called stands" of the drill string 11 are progressively uncoupled at the surface, the free upper ends of the hauling line 47 may be pulled downwardly through each uncoupled section to facilitate the removal of the drill pipe from the borehole 12. Alternatively, as seen in FIG. 3, when the drill string 11 is ready to be removed from the borehole 12, the upper ends of the hauling line 47 are connected to a suitable float 48 adapted to easily pass through the drill pipe so that it will be left floating on the surface of the mud column 49 in the borehole when the lastjoint or stand of the drill string has been removed. The float 48 can, of course, then be easily retrieved for disconnecting the hauling line 47 from the float.

Accordingly, as seen in FIG. 4, once the drill pipe 11 is out of the borehole 12, one end of the hauling line 47 can be secured, as at 51, to a cable-suspended well tool 52. Then, by simply pulling on the other end of the hauling line 47, the well tool 52 and its suspension cable 56 can be readily pulled downwardly through the borehole 12 to any position therein above the extended anchoring device 10. It will be recognized, of course, that since extreme forces may sometimes be required to move the well tool 52 and its suspension cable 56 through highly deviated or obstructed intervals of the borehole 12, the hauling line 47 should have substantial tensile strength. Once the well tool 52 has reached a desired location within the borehole 12, it may be retrieved in the usual manner by simple respooling the suspension cable 56 on a typical powered winch (not shown) at the surface-Moreover, if it is desired to move the well tool 52 back and forth between various locations within the borehole 12, the suspension cable 56 may be reeled in to move the well tool from one location to another higher location and the hauling line 47 may be used to return the well too] and its suspension cable to lower locations.

hauling line 47 may either be removed or, if desired, another cable-suspended well tool (not shown) canbe coupled thereto and pulled into the borehole in the same manner as previously described. Then, when the final well-completion operation has been finished by practicing the methods of the present invention, the hauling line 47 is easily retrieved by freeing one end and reeling in the other end thereof to pull the free end of the hauling line completely through the pulley 45 and back to the surface. It will be appreciated, of course, that once the anchoring device 10 is in place, it cannot be removed intact. Thus, it is preferred to fabricate thevarious elements of the anchoring device 10 and messenger sub 41 from materials which can easily be drilled by typical drilling bits (not shown) should the borehole 12 be further deepened. Typical of such materials would either be aluminum, cast iron, or similar easily drillable metals or else some of the more rugged and durable plastics such as a fiberglass epoxy.

Turning now to FIG. 5, an alternative embodiment is shown of new and improved apparatus also arranged in accordance with the principles of the present invention. It will, of course, be appreciated from a comparison of FIG. 5 with the preceding FIGS. that the anchoring device 100 is similar in many respects to the anchoring device 10 and needs only a limited description. In general, the anchoring device 100 carries a pulley 101 over which the doubled hauling line 47 is arranged and is adapted to be dispatched through the drill string 11 after the lower end thereof is positioned in the borehole 12. To accomplish this, the anchoring device 100 is provided with one or more normally retracted, upwardly diverging wall-engaging members 102 and 103 that are biased outwardly for movement into anchoring engagement with the wall of the borehole 12 once the anchoring device emerges from the o en, lower end of the drill string 11. Thus, in contrast to the previously described anchoring device 10, the anchoring device 100 can be anchored at intermediate locations in the borehole 12 and no particular manipulation of the drill pipe 11 is required.

Accordingly. as depicted in FIG. 5, the anchoring device 100 includes a tubular housing 104 adapted for passage through the drill string 11. If desired, one or more packing elements or swab cups 105 can be arranged around the housing 104 to provide a sliding fluid seal with the interior wall of the drill pipe 11. The anchoring members 102 and 103 are pivotally mounted, as by a single transverse pivot 106, within the housing 104 and adapted to be moved outwardly from their illustrated retracted positions through longitudinal slots 107 and 108 on opposite sides of the tubular housing. To bias the anchoring members 102 and 103 toward their extended positions, one or more springs, as at 109 and 110, are operatively connected between the housing 104 and suitably arranged crank arms or offset extensions 111 and 112 from the lower ends of the anchoring members. It will, of course, be appreciated that the anchoring device 100 is also preferably made of readily drillable materials.

Turning now to FIG. 6, an alternate embodiment is shown of an anchoring device 200 that is quite similar to the anchoring device 100 but includes means for subsequently recovering the anchoring device 200 after it has been anchoringly engaged in the borehole 12. As illustrated, the anchoring device 200 differs significantly from the previously described tool 100 only by the inclusion of an armreleasing mechanism 201 including an axially shiftable actuating rod 202. having a pair of depending arms 203 and 204 on its lower end respectively coupled by stout links 205 and 206 to laterally offset extensions 207 and 208 from the lower ends of the pivoted anchor- Once the well tool 52 is removed from the borehold 12, the

ing members 209 and 210. To urge the anchoring members 209 and 210 outwardly once the anchoring device 200 has emerged from the lower end of the drill string 11, a stout compression spring 211 is mounted between an enlarged shoulder 212 on the rod 202 and an inwardly projecting support 213 that is releasably secured, as by shear pins 214 and 215, to the housing 216 of the anchoring device.

Thus, after the pivoted members 209 and 210 have been extended to move their upper ends into anchoring engagement with the walls of the borehole 12, downward movement of the actuating rod 202 will be effective to pivot the anchoring members back to their initial retracted position (as illustrated in FIG. 6). To shift the actuating rod downwardly, one or more upstanding arms, as at 217 and 218, are arranged on the upper end of the rod 202 so as to straddle the pulley 219 mounted on top of the housing 216. By arranging the upright arms 217 and 218 to extend above the pulley 219, as a cablesuspended well tool (not shown in FIG. 6) is pulled downwardly by the hauling line 47, the lower end of the well tool can be moved into engagement with one or both of the upstanding arms 217 and 218 to drive the rod 202 downwardly for retracting the anchoring members 209 and 210. To prevent the subsequent reextension of the anchoring members 209 and 210, an enlarged shoulder 220 is arranged on the actuating rod 202 to be driven downwardly against the releasably secured support 213 and disrupt the shear pins 214 and 215 as the actuating rod is driven downwardly either by the weight of a well tool coupled on the hauling line 47 or by the impact of a so-called go-devil" (not shown) slidably dispatched along the hauling line. Once the shear pins 214 and 215 are disrupted, the spring 211 will no longer be effective to urge the anchoring members 209 and 210 outwardly from their retracted positions as the anchoring device 200 is being retrieved from the borehole 12.

It will be recognized that, in some situations, the downwardly traveling messenger (41, 100 or 200) may tend to rotate in relation to the drill string 11 so as to twist the doubled hauling line. To prevent this from occurring, the pulleys 45, 101 and 219 may be arranged on a suitable swivel joint (as at 221 in FIG. 6) for free rotation about the longitudinal axis of their respective messenger (41, 100 or 200). Other techniques may also be employed. For example, as shown in FIG. 4, a plurality of line-spacing members 53 may be operatively arranged at frequent intervals along the length of the doubled hauling line 47 and respectively adapted for releasably coupling the two portions of the hauling line together. In one manner of accomplishing this, each of the line-spacing members 53 may include a small body 54 coaxially mounted around one of the two halves of the doubled hauling line 47 and either bonded or temporarily secured thereto. One end of a transverse link 55 is pivotally or yieldably mounted on one side of the body 54 and its other end is appropriately notched or slotted for snugly receiving the other of the two halves of the doubled hauling line 47. By forming at least these transverse links 55 of a fairly rigid but partially resilient material such as an elastomer or plastic, the two halves of the doubled hauling line 47 will be kept apart as the line is being moved downwardly along the drill string 11. Then, as depicted in FIG. 4, as the well tool 52 is being pulled into the borehole 12, the lower downwardly traveling half of the hauling line 47 will slide through the slotted ends of the transverse links 55 as they are being carried upwardly by the upwardly traveling half of the hauling line. As the well tool 52 reaches each of the transverse links 55, the nose of the tool will readily disengage the slotted end of each link from the lower half of the hauling line 47 and swing the links upwardly against their associated bodies 54 to enable the tool to easily pass the line-spacing members 53.

Alternatively, a plurality of elongated, relatively small flotation bodies, as at 113 in FIG. 5, may be mounted at suitable intervals along the half of the hauling line 47 that is to be pulled upwardly for moving a well too! downwardly into the borehole 12. in this manner, as the anchoring device 100 (or the messenger 41 or device 200) is being dispatched through the drill string 11, the upper half of the hauling line 47 will be buoyantly supported above its lower half. If desired, the buoyant bodies 113 may also include an elongated slot, as at 114, along one side thereof sized and adapted for snugly, but releasably, coupling the lower half of the hauling line 47 thereto. Thus, as a well tool is being pulled into the borehole 12, its downward movement will progressively separate the lower downwardly traveling half of the hauling line 47 from its upwardly traveling half.

Accordingly, it will be appreciated that the present invention has provided new and improved methods and apparatus for reliably positioning cablesuspended well tools at desired locations in deviated well bores. When the apparatus depicted in FIGS. 1-4 is being employed, the anchoring device is first set by manipulation of the drill string and then the messenger sub is dispatched through the drill pipe to draw the doubled hauling line into the well bore. On the other hand, when the apparatus depicted in either FIG. 5 or P16. 6 is used to practice the present invention, the anchoring device itself is used to pull the doubled hauling line into the well bore as the anchoring device is dispatched through the drill string. In any event, after the anchoring device is securely anchored and the doubled hauling line is secured thereto, the drill string is removed to leave the hauling line extending from the surface to the anchoring device. Once this is accomplished, cablesuspended well tools may be readily pulled by the hauling line to any location in the well bore above theanchoring device.

Iclaim:

1. A method for positioning a well tool in a well bore below an obstacle therein to the free downward travel of such a well tool and comprising: lowering a pipe string into said well bore until its lower end is below said obstacle to provide an unobstructed messenger conduit between the surface and said lower end of said pipe string; dispatching into said pipe string a messenger trailing a doubled hauling line having a length of at least twice that of said pipe string and movably carried on said messenger; anchoring said messenger within said well bore below said lower end of said pipe string; raising said pipe string out of said well bore over said doubled hauling line to clear said well bore for the subsequent passage of a well tool; coupling one end of said doubled hauling line to a well tool; and pulling upwardly on the other end of said doubled hauling line for moving said well tool downwardly through said well bore and past said obstacle.

2. The method of claim 1 wherein said well tool is coupled to a suspension cable having a length at least equal to that of said pipe string.

3. The method of claim 1 wherein said well tool has electri- I cally responsive means thereon and is coupled to a suspension cable including electrical conductor means and having a length at least equal to that of said pipe string; and further including the step of: operating said electrically responsive means from the surface while said well tool is below said obstacle.

4. A method for logging a well bore interval having at least a lower limit below an obstructed portion of the well bore limiting the free downward passage of a cable-suspended logging tool and comprising: lowering a pipe string into said well bore until its lower end is adjacent to a selected location below said lower limit to provide an unobstructed messenger conduit from above said obstructed portion to said selected location, dispatching into said pipe string a messenger movably carrying a doubled hauling line having a length of at least twice that of said pipe string and its ends trailing therebehind to the surface; anchoring said messenger at said selected location within said well bore; raising said pipe string out of said well bore over said doubled hauling line to clear said well bore for the passage of a logging tool; coupling one end of said doubled hauling line to a logging tool connected to a logging cable having a length at least equal to that of said pipe string; pulling on the other end of said doubled hauling line for moving said logging tool downwardly through said well bore to said lower limit of said interval with said logging cable extending therebehind to the surface; pulling on said logging cable for moving said logging tool upwardly through said well bore to at least the upper limit of said interval; and obtaining at least one logging record of the earth formations adjacent to said interval as said logging tool is being moved between said limits of said interval.

5. A method for positioning a cable-suspended well tool below an interval of a well bore obstructing the free downward travel of such a well tool and comprising: lowering pipe string into said well bore until the lower end of said pipe string is below said obstructing interval to provide an unobstructed conduit adapted for the passage of a body including normally retracted wall-anchoring means; movably coupling to said body the intermediate portion of a doubled hauling line having a length at least twice that of said pipe string; dispatching said body with the ends of said doubled hauling line trailing therebehind through said pipe string for moving said intermediate portion of said hauling line out of said lower end of said pipe string and anchoring said body within said well bore therebelow to extend said doubled hauling line through said pipe string across said interval and to the surface; raising said pipe string from said well bore over said doubled hauling line for clearing said well bore for passage of a well tool; coupling one end of said doubled hauling line to a well tool dependently connected to a suspension cable having a length at least equal to that of said pipe string; and pulling on the other end of said doubled hauling line for moving said well tool across said obstructing interval with said suspension cable extending through said well bore to the surface.

6. A method for logging a formation interval having at least a lower limit below an obstructed portion of the well bore preventing the free downward passage of a cable-suspended logging tool and comprising: lowering a pipe string into said well bore until its lower end is below said lower interval limit to provide a conduit thereto for the unobstructed passage of a messenger having outwardly biased normally retracted wall anchoring means and trailing a doubled hauling line having a length at least twice that of said pipe string and carried over a pulley on said messenger; dispatching said messenger and said doubled hauling line through said pipe string for moving said messenger out of said lower end of said pipe string with said doubled hauling line extending therethrough to the surface and releasing said wall-anchoring means for extension into anchoring engagement within said bore below said lower limit; raising said pipe string out of said well bore over said doubled hauling line; coupling one end of said doubled hauling line to a logging tool dependently connected to a logging cable having a length at least equal to that ofsaid pipe string; pulling on the other end of said doubled hauling line for moving said logging tool downwardly through said well bore to at least said lower limit of said formation interval with said logging cable extending therefrom to the surface; pulling on said logging cable for moving said logging tool upwardly through said well bore to at least the upper limit of said formation interval; and obtaining a logging record of said formation interval as said logging tool is moving between said spaced limits thereof.

7. The method of claim 6 further including the step of: alternately pulling on said other end of said hauling line and then pulling on said logging cable for repetitively moving said logging tool back and forth between said spaced limits of said formation interval to obtain successive logging records thereof. 7

8. A method for positioning a cable-suspended well tool at a selected location in a well bore below a portion thereof presenting an obstacle to the free downward travel of such a well tool and comprising: releasably coupling the lower end of a pipe string to anchoring means adapted to be selectively engaged with the walls of a well bore and having first coupling means thereon adapted for coupling to a messenger moved downwardly through said pipe string to said anchoring means; lowering said pipe string into said well bore until said anchoring means are below said selected location and then moving pulley trailing therebehind a doubled hauling line of a length at least twice that of said pipe string; moving said messenger downwardly in said pipe string until said first and second coupling means are coupled together to anchor said messenger below said selected location and leave said doubled hauling line extending upwardly therefrom through said drill pipe to the surface; raising said pipe string out of said well bore over said doubled hauling line for clearing said well bore for the passage of a well tool; coupling one end of said doubled hauling line to a well tool dependently connected to a suspension cable having a length at least equal to that of said pipe string; and pulling on the other end of said doubled hauling line for moving said well tool through said well bore to said selected location with said suspension cable extending therebehind to the surface.

9. A method for logging a well bore interval having at least a lower limit thereof below a portion of the well bore presenting an obstacle to the free downward vpassage of a cablesuspended logging tool and comprising: releasably coupling the lower end of a pipe string to anchoring means adapted to be selectively moved outwardly against the walls of a well bore in response to a predetermined manipulation of said pipe string and having first coupling means thereon adapted for coupling to a messenger moved downwardly through said pipe string to said anchoring means; lowering said pipe string into said well bore until said anchoring means are below said lower interval limit and then manipulating said pipe string to move said anchoring means outwardly into anchoring engagement with the walls of said well bore; dispatching into said pipe string a messenger having second coupling means thereon and carrying a pulley trailing therebehind a doubled hauling line of a length at least twice that of said pipe string until said first and second coupling means are coupled together for positioning said messenger below said lower interval limit with said doubled hauling line extending therefrom through said drill pipe to the surface; raising said pipe string from said well bore over said doubled hauling line for clearing said well bore for the passage of a logging tool; coupling one end of said doubled hauling line to a logging tool dependently connected to a logging cable having a length at least equal to that of said pipe string; pulling on the other end of said doubled hauling line for moving said logging tool downwardly through said well bore to said lower limit of said interval with said logging cable extending therefrom to the surface; pulling on said logging cable for moving said logging tool upwardly through said well bore to at least the upper limit of said interval; and obtaining a logging record of the earth formations traversed by said well bore interval as said logging tool is moving between said spaced limits of said well bore interval.

10. The method of claim 9 further including the step of: alternately pulling on said other end of said hauling line and then pulling on said logging cable for repetitively traversing said logging tool back and forth along said well bore interval to obtain successive logging records of the earth formations adjacent thereto.

11. Apparatus adapted for positioning well tools at selected locations below obstructions in well bores and comprising: a body having a longitudinal axis; anchoring means operatively arranged on said body for movement relative thereto from a retracted position outwardly against an adjacent well bore surface; actuating means on said body and adapted for moving said anchoring means outwardly into anchoring engagement with such a well bore surface; line-carrying means having a downwardly facing surface transverse to said longitudinal axis and adapted for carrying a doubled hauling line having its looped portion passing under said line-carrying means along said transverse surface and its end portions on opposite sides of said line-carrying means and extending thereabove for lon' gitudinal movement therearound; and means adapted for connecting said line-carrying means to said body above said anchoring means.

12. The tool-positioning apparatus of claim 11 wherein said body is sized and adapted for passage through a pipe string temporarily positioned in a well bore; and said actuating means include spring means adapted for urging said anchoring means outwardly into anchoring engagement with such a well bore surface whenever said body emerges from the lower end of such a pipe string.

13. The tool-positioning apparatus of claim 12 further including sealing means on said body sized and adapted for providing a sliding seal with the interior walls of such a pipe string.

14. The tool-positioning apparatus of claim 12 wherein said line-carrying means include a pulley adapted for carrying such a doubled hauling line, and a transverse shaft journably carrying said pulley; and said connecting means include a support secured to said body and said pulley for supporting said pulley in an upright position for rotation about said pulley shaft.

15. Apparatus adapted for positioning cable-suspended well tools in a well bore below an obstacle therein to the travel of such well tools and comprising: a first body having a longitudinal axis; anchoring means operatively arranged on said first body and including at least one wall-engaging member having one end adapted to be anchored in an adjacent wall of a well bore, pivot means on said first body and pivotally supporting said wall-engaging member thereon for lateral movement from a retracted position to anchor said one end thereof in such a well bore wall; actuating means including an actuating member mounted on said first body and adapted for longitudinal movement thereon between first and second relative positions, means interconnecting said actuating member and said wall-engaging member and adapted for moving said wallengaging member outwardly to its said extended position upon movement of said actuating member to its said second position, and means releasably retaining said actuating member in its said first position; means adapted for releasably connecting said actuating member to a pipe string for movement thereby into a well bore, said connecting means being releasable in response to a predetermined movement of such a pipe string relative to said actuating member so as to permit withdrawal of such a pipe string from said first body once said wall-engaging member is in its said extended position; a second body adapted for passage through a pipe string connected to said actuating member; and upright pulley operatively mounted on said second body for rotation about a transverse axis and adapted for carrying the looped portion of a doubled hauling line passed under said pulley with its end portions on opposite sides thereof and extending thereabove; and first and second coincidentally aligned coupling means respectively mounted on the upper end of said first body and on the lower end of said second body and adapted to be coupled together upon movement of said second body down a pipe string carrying said first body bringing said first and second coupling means together.

16. The apparatus of claim 15 further including: a doubled hauling line operatively mounted on said pulley and having elongated portions adapted to be trailed therebehind to the surface as said second body is moved down such a pipe string carrying said first body.

17. The apparatus of claim 16 further including: means operatively arranged on one of said elongated line portions of said hauling line and releasably coupled to the other of said elongated line portions thereof for preventing entanglement of said doubled hauling line as said second body is moved down such a pipe string.

18. The apparatus of claim 17 wherein said means on said one line portion include a plurality of buoyant bodies secured at spaced intervals along said one line portion and said releasable coupling means include means on each of said buoyant bodies adapted for releasably retaining said other line portion thereon.

19. Apparatus adapted for positioning cable-suspended well tools in a well bore below an obstacle therein to the travel of such well tools and comprising: a body having a longitudinal axis and adapted for passa e through a pipe string temporarily positioned in such a well ore; anchoring means operatively arranged on said body and including at least one wall-engaging member having one end adapted to be anchored in an adjacent wall of a well bore, pivot means on said body and pivotally supporting said wall-engaging member thereon for lateral movement from a retracted position to an extended position to anchor said one end thereof in such a well bore wall; actuating means including spring means operatively coupled between said body and said wall-engaging member for urging its said one end outwardly to said extended position and against the wall of such a well bore once said body emerges from such a pipe string; and an upright pulley operatively mounted on the upper end of said body for rotation about a transverse axis and adapted for carrying the looped portion of a doubled hauling line passed under said pulley with its end portions on opposite sides thereof and extending thereabove.

20. The apparatus of claim 19 further including: means adapted for selectively returning said wall-engaging member to its said retracted position and including means releasably coupling said spring means to said body and adapted to release upon application of a predetermined force thereto, a forcetransmitting member movably mounted on said body between said releasable coupling means and a position above said pulley and adapted to be forcibly driven downwardly against said releasable coupling means upon impact thereagainst of a well tool moving downwardly along a hauling line carried by said pulley, and means interlinking said force-transmitting member to said wall-engaging member for returning said wall-engaging member to its said retracted position upon downward movement of said force-transmitting member.

21. The apparatus of claim 19 further including: a doubled hauling line operatively mounted on said pulley and having elongated portions adapted to be trailed therebehind to the surface of said body is moved down such a pipe string.

22. The apparatus of claim 21 further including: means operatively arranged on one of said elongated line portions of said hauling line and releasably coupled to the other of said elongated line portions thereof for preventing entanglement of said doubled hauling line as said body is moved down such a pipe string.

23. The apparatus of claim 22 wherein said means on said one line portion include a plurality of buoyant bodies secured at spaced intervals along said one line portion and said releasable coupling means include means on each of said buoyant bodies adapted for releasably retaining said other line portion thereon. 

